1. Field of the Invention
This invention relates to a vehicle room lamp that illuminates the interior of a vehicle such as an automobile, more particularly, to a room lamp that provides illumination of a desired light color in addition to a normal room lamp.
2. Description of the Related Art
Generally, a conventional room lamp is mounted on the center of the roof inside a vehicle. The room lamp has a bulb as a light source housed therein. The bulb is lit to illuminate the cabin. On the other hand, a fluorescent lamp is used as a room lamp in some automobiles such as a mini van or a sport utility vehicle, e.g. in order to give a luxurious feeling to the interior of the vehicle.
In recent years, users have acquired a wide variety of preferences, and their sense of value also has become very diversified. Accordingly, the equipment provided within a car""s interior should provide its users with as many design choices as possible from a variety of viewpoints and decorating styles. However, the conventional room lamp is commonly required to give a sufficient illumination to the cabin only in the nighttime or the like. Namely, it is used from a functional viewpoint, and its main purpose is to light up the interior of the cabin. Therefore, its light color is limited to one color, e.g. white, which is the color of the installed bulb or fluorescent lamp. Moreover, the lamp is operated in only three modes, i.e. an on mode, an off mode and a door link mode in which it is switched on and off in accordance with the opening and closing of a door. In short, the conventional vehicle room lamp is limited in its variety of design and decoration style. Thus, it can be improved from an ornamental viewpoint. Furthermore, in order to prevent the interior light from disturbing the driver while driving, the conventional vehicle room lamp is switched off and never operated during operation of the vehicle. In addition, some colors, for example, red, may be prohibited by the traffic laws of certain countries, so that the design is limited from this aspect, as well.
An object of the present invention is to provide a vehicle room lamp that can give a wide variety of illumination modes, as well as many design choices.
According to a first embodiment of the invention, a vehicle room lamp comprises a plurality of light emitting diodes (LEDs) disposed on the roof of a vehicle""s cabin at fixed intervals. Control means controls the light emission of the LEDs to illuminate the cabin.
According to a second embodiment of the invention, a vehicle room lamp comprises a direct lighting unit attached to the roof of the vehicle""s cabin so as to illuminate the light directly into the cabin. An indirect lighting unit has a plurality of LEDs disposed on the roof at fixed intervals and controls the light emission of the LEDs so that the LEDs illuminate the roof, thereby indirectly illuminating the cabin.
According to a third embodiment of the invention, a vehicle room lamp comprises a housing attached to a roof of the vehicle""s cabin and surrounding the outer circumference of a room lamp unit for illuminating the cabin. The housing contains a plurality of LEDs. The LEDs are capable of emitting three primary colors of light. A light guide projects the light of the LEDs within the cabin so as to define a planar light source. A control circuit controls the light emission of the LEDs. A switch initiates the control operation of the control circuit.
According to a fourth embodiment of the invention, a vehicle room lamp comprises a housing attached to the roof of a vehicle""s cabin. An LED is disposed in the housing so as to emit a light toward the cabin. A lens is disposed on the housing so as to face the light emission side of the LED. The lens vertically converges at least at a lower portion of the diffused light of the LED that travels to the roof with a downward inclination, thereby transforming at least the lower portion of the diffused light into a light composed of rays substantially parallel to the roof. The parallel rays are directed to radiate to the cabin.
Further objects and advantages of the invention will be apparent from the following description, reference being had to the accompanying drawings, wherein preferred embodiments of the invention are clearly shown.